Objective To evaluate the safety and efficacy of one-level posterior lumbar interbody fusion(PLIF) combined with Prospace and facet fusion using local autograft. Methods Clinical and radiographic data of 76 patients treated by this technique was reviewed from May 2002 to December 2004. Of them, there were 52 males and 24 females, with an average age of 53.2 years (23-81 years), including 60 cases of degenerative disc disease, 9 cases of failed back surgery syndrome and 3 cases of spondylolysis. The disese courses were 1.2-8.7 years (mean 3.6 years). The levels of PLIF were: L2,3 in 2 cases, L3,4 in 7, L4,5 in 54, L5/S1 in 10, L4/S1 in 1 and L5,6 in 2. After decompression, Prospace was inserted into interbody space bilaterally,and located in disc space 4 mm beyond the rear edge of the vertebral body. Local laminectomy autograft was packed both laterally into and between 2 implants. Then the remanent local autograft was placed over facet bed. Pedicle screws were used after insertion of Prospace. Clinical results were evaluated by the JOA score. Disc height ratio and lumbar lordosis angles were measured on lateral radiographs. Fusion status was determined by evidence of bridge trabeculae across facet joint and interbody space on CT scan without mobility in lateral dynamic X-rays, and no radiolucent gap between Prospace and endplate. Paired t-test was used for statistical analysis. Results Mean blood loss and operative time was 384 ml and 178 minutes, respectively. The average JOA score at final follow-up (26.1 + 2.7) was significantly improved when compared with that of pre-operation (14.5 ± 4.0, P ＜ 0.05), with a mean recovery rate of JOA score 81.1% (37.5%-100.0%). The fusion rate was 97.4% (74/76). Mean disc height ratio and the involved segmental lordosis angle were increased from preoperative 0.27 ±0.07 and 5.8 + 2.2° to 0.33 + 0.06 and 11.3 + 2.0° respeetively at the final follow-up, and the differences were significant ( P ＜ 0.05). There were no device-related complications. Conclusion This surgical technique combined with Prospace interbody device is a safe and effective surgical option for patients with one-level lumbar disorders when PLIF is warranted.

Objective To study the clinical effects of the artificial vertebral body of the biomimetic nano-hydroxyapatite/polyamide 66 (n-HA/PA66) composite for the structural reconstruction and the height restoring of the vertebral body in the thoracolumbar fractures by the anterior surgical procedures. Methods From December 2003 to January 2006, 42 patients with thoracolumbar fractures received the anterior surgical procedures to decompress and reconstruct the spinal vertebral structure with the artificial vertebral body of the n-HA/PA66 composite. Among the patients, there were 28 males and 14 females, aged 17-67 years, averaged 43.6 years. The thoracolumbar fractures developed at T12 in 5 patients, at L1 in 17, at L2 in 14, and at L3 in 6. The height of the anterior border of the vertebral body amounted to 29%-47% of the vertebral body height, averaged 40.6%. The Cobb angle on the sagittal plane was 21-38° averaged 27.6°. According to the Frankel grading scale, the injuries to the nerves were as the following: Grade A in 7 patients, Grade B in 19, Grade C in 8, Grade D in 6, and Grade E in 2. Results All the 42 patients were followed up for 6-25 months. Among the patients, 36 were reconstructed almost based on the normal anatomic structure, and 6 were well reconstructed. The mean height of the anterior border of the vertebral body was 40.6% of the vertebral body height before operation but 91.7% after operation. And the reconstructed height of the vertebra was maintained. The mean Cobb angle on the sagittal plane was 27.6°before operation but 13.4° after operation. All the patients had a recovery of the neurological function that had a 1-grade or 2-grade improvement except 7 patients who were still in Grade A and 2 patients who were in Grade D. The implant was fused 3-5 months after operation. No infection, nail break, bar/plate break or loosening of the internal fixation occurred. Conclusion The artificial vertebral body of the biomimetic n-HA/PA66composite can effectively restore the height and the structure of the vertebra, can be fused with the vertebral body to reconstruct the spinal structural stability effectively, and can be extensively used in the clinical practice.

Objective To evaluated the role of wt-P53 protein in telomerase regulation in keloid fibroblasts(KFBs). Methods The fibroblasts were derived from human keloid tissue which was proved by pathological diagnosis. KFBs were divided into 2 groups, the transfection group and the untransfection group. wt-p53 gene was transfected into the fibroblasts by adenovirus vectors in the transfection group. The KFBs untransfected with wt-p53 gene served as control (untransfection group). After 48 hours of transfection, the expression of wt-P53 protein was analyzed by both Western blotting and immunofluorescence method, respectively. The telomerase activity was evaluated by TRAP-ELISA after 1-7 days of transfection.Results All the KFBs from 2 groups expressed wt-P53 protein. But the expression level of wt-P53 protein in the transfection group was significantly higher than that in the untransfection group. At the same time of high expression of wt-P53 protein, the telomerase activity of KFBs in transfection group was significantly lower than that in the untransfection group( P＜0.05). Conclusion High level expression of wt-P53 protein can transiently inhibit the telomerase activity of KFBs.

Objective To review and summarize the latest development of the therapy for the Duchenne muscular dystrophy (DMD). Methods The recently-published articles related to the therapies for DMD were extensively reviewed and briefly summarized. Results The therapeutic approaches for DMD included the gene therapy, the cell therapy, and the pharmacological therapy.The gene therapy and the cell therapy were focused on the treatment for the cause of DMD by the delivery of the missing gene, the modification of the mutated gene, and the transfer of the normal cells including the stem cells, while the pharmacological therapy dealt with the downstream events caused by the dystrophin gene defect, slowed down the pathologic progress of DMD, and improved the DMD patient's life quality and life span, by medication and other factor treatments. Conclusion There is still no cure for DMD because of various difficulties in replacing or repairing the defected gene and of the multifaceted nature of the severe symptoms. Therefore, it is imperative for us to find out a more effective treatment that can solve these problems.

Objective To evaluate proton MR spectroscopy (1H-MRS) for detection of the motor cortex and adjacent brain in amyotrophic lateral sclerosis (ALS) patients with apparent upper motor neuron involvement after olfactory ensheathing cells(OECs) transplantation. Methods From December 2004 to February 2005, 7 patients with clinically definite ALS who could safely undergo MRS were admitted into the perspective study. The neurological status, ALS functional rating scale (ALSFRS), EMG, and 1H-MRS taken before and 2 weeks after operations were carefully analyzed. The NAA/Cr and Cho/Cr ratios were measured in the cerebral peduncle, genu and posterior limb of the internal capsule, corona radiata and precentral gyrus. Results The ALSFRS in 2 cases improved obviously whose ALSFRS increased from 30 to 33 and from 29 to 34 respectively. And 5 cases remained stable 2 weeks after OECs transplantation. Statistical analyses for all seven cases showed both the NAA/Cr and Cho/Cr ratios decreased, but in the two cases with ALSFRS improvement the NAA/Cr increased in the certain anatomic position which confirmed the neurological and EMG findings. Conclusion The proton MR spectroscopy is a suitable noninvasive measure for ALS evaluation. The preliminary study suggests that two of the seven ALS cases improved apparently short-term after OECs transplantation. More patients are required for the clinical study and longer follow-up duration is needed for future research.

Objective To investigate the possible signaling mechanisms by which recombinant human platelet-derived growth factor (rhPDGF) accelerated healing of cutaneous wound in diabetic rats. Methods Four full-thickness skin wounds were incised in the back of 26 male Wistar diabetic rats. The wounded rats were divided into 3 groups (7 or 8 rats each group). One group without treatment was used as a control, and the other 2 groups were treated with rhPDGF at a dose of 7.0 μg/cm2 wound or vehicle ( DMSO/0.9%NaCl, vol/vol 1:1) from 1 to 14 days. The wound healing was evaluated by the measurements of the wound volume and area. Immunofluorescent and immunohistochemical staining were used to examine the phosphorylation of extracellular signal-regulated kinase 1/2(ERK1/2) and the expression of proliferative cell nuclear antigen (PCNA), respectively. Results Granulation tissue appeared in the bed of wound after injury. The number of blood capillary buds and fibroblasts was greater in the rhPDGF-treated group than that in the other 2 groups. A lot of inflammatory cells infiltration and collagen deposition were observed in the wound. The wound-volume in the rhPDGF-treated group was smaller than that in control group ( P ＜ 0.05). The reepithelialization rate in rhPDGF-treated group was higher than that in the other 2 groups at 7 days after injury ( P ＜ 0.05). The expression of PCNA in reparative cells was higher in rhPDGF-treated group than in control group or vehicle-treated group at 3,7 days after injury( P ＜ 0.05). The phosphorylation of ERK1/2 was stronger in rhPDGF-treated group than that in control group or vehicle group at 7 and 14 days after injury( P ＜ 0.05). Conclusion These results suggest that rhPDGF accelerates wound healing and improves healing quality by increasing the phosphorylation of ERK1/2.

Objective To compare the clinical outcomes of posterior lumbar interbody fusion(PLIF) using simple cage alone fusion with pedicle screw fixation and autogenous bone grafting and cage fusion with pedicle screw fixation in adult spondylolisthesis. Methods From March 2003 to March 2004,Twenty-seven patients with lumbar spondylolisthesis were divided in two groups. In group A, 15 patients were treated by PLIF using simple cage alone fusion with pedicle screw fixation, including 4 males and 11 females, aging 53-68 years. Isthmic defects were located at L4 in 9 cases, at L5 in 6 cases. Four patients were smokers. The preoperative mean disc space height was 5.4±2.3 mm, the mean percentage of slip was 36.8%±7.2%. In group B, 12 patients were treated by PLIF using autogenous bone grafting and cage fusion with pedicle screw fixation, including 3 males and 9 females, aging 56 years. Isthmic defects were located at L4 in 8 cases, at L5 in 4 cases. Five patients were smokers. The preoperative mean disc space height was 5.7±2.5 mm, the mean percentage of slip was 37.8%±6.2%. Two groups were compared in the amount of blood loss, duration of hospitalization, back pain, radiating pain, fusion rate, the intervertebral disc space height, the postoperative degree of slip and the fusion rate. Results All patients were followed up for 24-38 months. The mean follow-up was 29(24-36) months in group A and 26(24-38) months in group B. There were no statistically significant differences in follow-up period, age,sex, the location of isthmic defects, smoking, the preoperative disc space height and the percentage of slip between two groups (P>0.05). There were no statistically significant differences in the amount of blood loss, the duration of hospitalization, the fusion time between two groups(P>0.05). But there were statistically significant differences in the back pain score, the radiating pain score and the fusion rate between two groups(P<0.05).The postoperative disc space height and the degree of slip of the last follow-up were 5.8±2.2 mm and 25.6%±7.2% in group A, 6.2±2.5 mm and 24.1%±7.4 % in group B, showing statistically significant difference (P<0.05). Conclusion The PLIF using autogenous bone grafting and cage fusion with pedicle screw fixations is more beneficial to improving the fusion rate and preventing long-term instabilities than simple cage alone fusion with pedicle screw fixation in adult spondylolisthesis.

Objective To study the effect of dexamethasone to protect flaps from an ischemia-reperfusion injury and elucidate its mechanism of regulating the death course of the neutrophils. Methods The rats were randomly divided into 3 groups.The vein of the rat was clamped for 8 h after the flap had formed. Group A: the normal flap; Group B: the saline control flap; Group C: the treatment flap with dexamethasone. The survival area of the flaps was measured at 7 days; the apoptotic and necrotic neutrophils,tumor necrosis factor α (TNF-α), and interleukin 10 (IL-10) concentrations were measured. Results The flap survival are as in Groups A and C were larger than those in Group B. The apoptotic neutrophils in Group B were fewer than those in Groups A and C on the 1st and 3rd days after operation; however, they were more in number in Group B than in groups A and C on the 6th day. The necrotic cells in Group B were more in number than those in Groups A and C. In Group B, the plasma TNF-α concentration reached the maximum level at 1 h,while the IL-10 level reached the lowest 3 h after the reperfusion. In Group C, the TNF-α concentration was lower than that in Group B and decreased dramatically at 6 h. The IL-10 concentration was the lowest at 1 h, and increased rapidly at 3 h.Thus,ischemia-reperfusion could injure the flaps, probably through the abnormal action of the neutrophils, such as the disordered secretion of the cytokines and abnormal death course of the neutrophils. Conclusion Dexamethasone can protect the flap from an ischemia-reperfusion injury by its regulation for the neutrophil function.

Objective To investigated the distribution of epidermal stem cells in rat full-thickness wound tissues during the wound healing process and to elucidate the roles of epidermal stem cells in wound repair in vivo. Methods Eighty circular full-thickness wounds were produced on both sides of the back in 20 male Wistar rats labeled with BrdU 60 days previously (4 wounds in each rat). BrdU, β1 integrin and keratin 19 (K19) were employed to determine the epidermal stem cells with SP immunohistochemical methods, and the epithelialization was determined with routine histological methods of HE staining on the 3rd, 7th, 14th, and 21st days after operation. Results No cells with positive immunostaining for β1 integrin, K19 and BrdU were found in granulation tissue of wound in both groups during the healing process. However, a few scattered β1 integrin and K19 positive cells were found within the stratum spinosum and stratum granulosum of the epidermis on the wound edges on the 3rd day post-injury. And these positive cells gradually became more and more in number, and mostly concentrated on the border of wound edges till the wounds healed. In addition, the number of positive cells for β1 integrin and K19 in the infected wounds was less than that in non-infected wounds. These positive cells for β1 integrin and K19 staining on the wound edge were also positively stained with BrdU in the cellular nuclei. Conclusion The above results indicate that ectopia of epidermal stem cells present a major function during wound epithelialization.

Objective To determine the safety of the fetal olfactory ensheathing cell(OEC) transplantation in patients with chronic spinal cord injury (SCI) by examination of the magnetic resonance imaging (MRI). Methods A prospective clinical study involving 16 patients with chronic SCI was designed to investigate the feasibility and biological safety of the fetal OEC transplantation in treatment of SCI. The olfactory bulbs from the 3-4-month-old aborted human fetuses following the strict ethical guidelines were harvested and trypsinized down to single fetal OEC. These cells were then cultured for 12-17 days and were prepared for a clinical use. From November 2001 to December 2002, 16 patients with chronic SCI were randomly enrolled. The patients suffered from SCI for 1.5-8 years (average 4.3 years) after the injury. The suspension (50 μl) containing about 1×106 fetal OECs was transplanted by an injection into the patients' spinal cords above and below the injury site. All the patients were assessed before the transplantation and were followed up with MRI for 29-42 months (average 38 mon) after the transplantation. Results No cell-related adverse effects were observed in any patient during the follow-up period. The follow-up with MRI did not reveal any development of optic glial tumor, tumor-like mass, new hemorrhage, edema, expanding cyst, new cyst formation, infection or disruption of the neural structure in the transplant site of all the patients. Conclusion This is the first clinical study demonstrating the long-term safety of the OEC therapy for SCI. The results indicate that our protocol is feasible and safe in treatment of patients with chronic SCI within 38 months after the injury. Although the size of the samples for our study was not big enough, the positive results of the study have encouraged us to make a further research in this field.